Fix a bug for resetting the buffer (#3593)
Fix a bug for resetting the buffer (#3593)

For mapped device memories,the content will be copied from CPU to
GPU by the load instruction, so the effect of vkCmdCopyBuffee will
be invalidated by the copy from CPU to GPU.
pmuetschard/gapid,google/gapid,google/gapid,google/agi,pmuetschard/gapid,google/agi,pmuetschard/gapid,pmuetschard/gapid,google/agi,google/gapid,google/agi,pmuetschard/gapid,pmuetschard/gapid,google/gapid,google/gapid,google/gapid,google/agi,google/agi,google/agi,google/gapid,pmuetschard/gapid,google/gapid,pmuetschard/gapid,google/agi